“How about wind?” asked the Kantrick.
“I really don’t know how much of what we feel is due to our own motion,” Molly replied. “We should probably stop for a check some time, but that can wait awhile, I’d think. Jenny, you’re outside now. Have you left the storm area yet?”
“Yes. It’s a smallish cyclone only a couple of hundred kilometers across—rather surprising, considering Enigma’s rotation. Maybe the topography is making eddies. I’m in sunlight, as far as the clouds permit, over very hilly ground.”
“Hills or dunes?” asked Carol promptly.
“Hills. Quite solid. Not going anywhere.”
“Folds? Blocks? Volcanoes? What?”
“I don’t know. Folds, at a guess, with lots of erosion. Numerous dry streambeds.”
“Any really long rivers, cutting across ranges of hills?”
“Not that I’ve seen yet.”
“Good. Look hard for caves where the streambeds seem to enter or leave hills, particularly the former.”
“Good idea. I’ll be a long time covering the area, though.”
“Assume we have the time, lengthy friend.”
If Charley failed to grasp all the implications of this exchange, at least he asked no questions. He volunteered the boat’s position—heading rapidly for a point a hundred kilometers west of Jenny’s—and promised to start searching, too, as soon as he could see the ground. Joe said nothing.
For hours the two women raced through near-weightless darkness, not quite as helpless as roller-coaster riders. Jenny and Charley scanned Enigma’s surface, producing an excellent topographic map in the boat’s computer, but for a long time failing to find any caves with winds blowing either in or out. Joe completed another mapping robot, controlling himself in the face of the temptation to add even more safety and research equipment that might possibly be useful-yielding would have meant interrupting the work of the record-controlled shop equipment and adding much time to the project. Enigma rotated, but this made little difference to any of them; those who were on the surface were at a latitude where Arc never set at this season.
Molly slept again, and even Carol dozed, though she kept her great, side-placed, independent eyes open. It seemed unlikely that retracing their course would ever do them any good, but she was taking no risk of missing landmarks; everything her senses detected went firmly into memory, though her awareness was more concerned with earlier memories.
The dominant recollection during these hours was of her first meeting with Molly and Jenny, perhaps because it, too, had involved a trip. Carol had carelessly allowed her physical fitness rating at the School to lapse and was in the process of earning it back with a rather dangerous eight-hundred-kilometer hike on Jet, Smoke’s third planet; naturally, she had not been allowed to use a world with gravity weaker than that of her own. The Human colony was on Smoke’s inner planet and the Rimmore one on the fourth, both for reasons of gravity comfort, and Molly and Jenny had been at the starting point. Courtesy had naturally prevented Carol from asking either of the others why they were making the same trip—it could not be for her own reason, since both women were used to greater natural gravities—but it might of course have been something else embarrassing; and neither had volunteered the information. It might have been simply an interest in Jet’s native life, which like them was oxygen-breathing. In any case, enough had happened along the eight hundred kilometers, ranging from physically dangerous to merely interesting, to let each of the three be helpful to the others and lay the foundations of firm friendship. It had been Jenny who had suggested that they collaborate in the lab work still needed for their degrees, but the others had been enthusiastic.
The river was now too wide for their lights to reach across; whether rain seepage, lakes draining from the surface, or lakes already underground were feeding it none of them could guess. Wide as it was, it remained turbulent and presumably shallow.
The endless journey was taking nervous toll on everyone, not just the two travelers. Twice Charley called Molly on private channel to ask how long it was going to continue, and seemed surprised when she was irritated at the question. Charley was certainly not stupid, though these questions seemed to be; she had never suspected the theory behind his predictions and behavior. Had she even guessed at it, she would have been more tolerant of his seemingly senseless inquiries.
Then the Kantrick’s voice came through with something more interesting.
“There’s some sort of dust spout ahead!” he called. “I can’t make out details yet—this air is murky enough anyway. There’s a hill at its base, so maybe it’s a wind source like the cave you two went into. You should have been going downwind, I guess.”
Molly was as gentle as possible, consistent with the need to get her words in ahead of her companion. “Don’t guess just yet. Get a closer look, and make believe you’re writing it up for the School.”
“Oh, of course. It isn’t really much of a hill—I can see it better now as I get closer. If it’s piled up from underground the way yours must have been, it hasn’t been piling for long. The dark column rising from its middle still looks like dust, though.” He paused and keyed the boat still closer. “We need more of Joe’s regular robots to see what the wind is doing. I can’t tell whether there’s any horizontal component at all. Just a moment while I land beside it and see whether the dust is blowing or not.” No one said anything while this was accomplished. “The usual fine stuff; I’d call it drifting, not really blowing. Even Joe could walk around in it. I’ll lift again and see about the hilltop; it looks like one of those sand volcanoes you went into—lower and broader, as I said…”
“No, you didn’t.”
“Sorry, Carrie. As I meant to say. I’ll get right above it for a look straight down—there. Yes, there’s a crater, but it isn’t very deep, and the sand inside is churning violently—I’ll let down toward it. It looks as though the wind were coming up through the sand, lifting the lighter particles but not the heavy stuff—maybe if I block part of it with the boat the way I did the other, the wind will be hard enough to lift the bigger grains too and clear the way—that would open a passage for you folks.”
“Maybe by midsummer!” exclaimed the Shervah. “But try it if you like,” she added more tolerantly. “It will be interesting to see the shape of those grains, wouldn’t you say, Jenny?”
“Very” came the harsh answer. “I am tempted to interrupt the present search—but I won’t. I could go back to your first trap and probably get the same thing, I suspect; the situation doesn’t seem to be strange to Enigma. Be careful about getting too low, Charley.”
“Why? What could happen?”
“How heavy did you mean by ’heavy stuff? I don’t suppose it really matters—the boat’s pretty solid and nothing really big is likely to be carried by wind that hasn’t yet cleared all the dust out of that neck. Or were you counting on something’s happening? I was forgetting your prediction.”
“No—nothing of that sort. But maybe you’re right; I won’t get too low. In any case, I don’t see how the two of you could get through there unless the place was blown really clear—not in ordinary armor. Still, it’s good to know that there are more places where winds come from inside. It’s a pretty safe bet there are lots of them, if we’ve encountered three in such a short time.” No one commented. “The main question, I guess, Molly, is whether the wind is going in somewhere else, or the ice you’re hoping for is boiling somewhere below. I suppose it’s that hope that has you heading into the wind.”